Ted worked on the Aurora system for a number of years and, tbh, until I heard it I doubted that it would work. But it does work as he claimed and surpasses his earlier linear array system for imaging. Ted experimented extensively with reflectors and in-room sound. His 1971 Wireless World articles cover some of his ideas and there's a chapter about it in his 1962 Loudspeakers book. So no, it isn't hokey. Ted was first and foremost an engineer.
Patenting something like the Auroras is difficult, expensive and possibly impossible to do, so forgive me if I don't go into details. It is also why we don't offer the reflectors on their own. A customer did try and replicate the effect but ended up finding the Auroras did it better
EJ Jordan Aurora 800 - Customer Review - E J Jordan Designs
It's a shame that the speaker-room interface is so often always seen as an add-on to selling a pair of boxes. There have been some imaginative solutions offered in the past which have resulted in really interesting loudspeaker designs.
Patenting something like the Auroras is difficult, expensive and possibly impossible to do, so forgive me if I don't go into details. It is also why we don't offer the reflectors on their own. A customer did try and replicate the effect but ended up finding the Auroras did it better
EJ Jordan Aurora 800 - Customer Review - E J Jordan Designs
It's a shame that the speaker-room interface is so often always seen as an add-on to selling a pair of boxes. There have been some imaginative solutions offered in the past which have resulted in really interesting loudspeaker designs.
Can you provide a link to the claim about how it works.
I cannot find anything like this current arrangement in the WW article. Have I missed it?
Why would you want to patent it given the small size of the business and having been manufacturing it for a few years?
Draw the path of the first reflection off the front wall in the direction of the listening position and then You will see how it works
no magic there, basic physics, well, often overlooked, that's for sure
Drawing reflection lines is a too simple "analysis". We must remember how wavelength affects sound dispersion.
What shape has the wall-side of the reflector , isn't it convex? How does it direct soundwaves to the wall?
The blade seems to be in the midline, it reflects only half of "energy" towards the listener. What if front wall is bricks/plasterboard, wood etc.?
What shape has the wall-side of the reflector , isn't it convex? How does it direct soundwaves to the wall?
The blade seems to be in the midline, it reflects only half of "energy" towards the listener. What if front wall is bricks/plasterboard, wood etc.?
I have some familiarity with how sound propagates and have some confidence in the physical processes present. However, I have not worked through the relative magnitudes or the influence of smearing in time from the diffraction off the edge. Tempting as it is state that it is hokey (not that I understand what hokey means in this case but it sounds derogatory) without doing the sums or an experiment one can only say it gives the appearance of being hokey. For example, Heckl, possibly the second most prestigious acoustical engineer in Germany at the time, was initially dismissive of the Manger driver before he did the sums. But that was before mainstream audiophile nonsense and so I doubt he would have bothered with the sums today.
You do realise the drivers are not pointed at the listener and each driver attempt to cover the whole frequency range? The panel is not centred on a driver but offset so the high frequencies will be mainly on one side. The curvature will further weaken the strength of the high frequency on the side near the wall while strengthening it on the other so the high frequency diffraction off the edges will have no tendency to cancel in the way it would if it was normal to a propagating sound wave. It is this diffraction which will create a direct sound field for the listener at high frequencies, followed shortly by a reflection off the front wall and with a smearing in time as diffracted sound reaches the ear from other parts of the edge. It might not be a disaster but then again...
it is simple but it tells most of the story
the thing can work in a sufficient frequency range
look carefully how it is positioned - it is not on the loudspeaker's acoustical axis
it redirects HF away from the front wall and to the sides (ipsilateral) - that's what it does
in a way it looks like a development of the classic JBL Paragon midrange section principle with the difference that the reflecting element is concave, not convex, slightly focusing instead of dispersing
There's science-theory and then there's science-practice - such as the value of using physics to anticipate when you will get a flat tire on your car. Knowing the physics of tires and nails on the pavement isn't too helpful when you start your car in the morning.
The theory part of reproducing sound in your room at home is contained in Toole's big book. It contains various postulates like, "you kind of need a balance between direct sound and ambient sound.....", "sounds arriving within 50 milliseconds....", "fussing about phase is crap...", and so on.
When you understand the theory, you have to then figure out how to apply it to your room.
I and all the folks who are enthusiastic about dipole speakers are getting a big chuckle out of a discussion premised on direct-radiating speakers. Kind of the way Mac users feel during discussions of viruses on Windows machines.
B.
Member
Joined 2009
Paid Member
Isn't that kind of looking down you nose a little ?
I like OB too. But many folk do not like to give their speakers the necessary breathing room, or they may be too restricted by room size. It's not just about differences between house sizes in different cultures - even in 'big' North America a child in University usually has a very small room. Where are the more innovative speaker designs for these situations (no - not Bluetooth!!) ?
Sorry for being insensitive to folks with small rooms. Wouldn't a dipole be beneficial? Or - are you ready - mono!
Dipole users would just chuckle with incomprehension in this thread but the reverse would be true in a discussion of EQ re sound arrival time.
B.
Last edited:
Hi Guys,
May I put up another question pls. Since the discussion is about the front wall reflections, how about the rear wall behind our listening seat, should it be totally absorbent instead of
the normally suggested which calls for diffusion. Would appreciate your thoughts on this. I have experimented with diffusion but the benefits don't seem to be as great as diffusion on the front wall
Thanks
May I put up another question pls. Since the discussion is about the front wall reflections, how about the rear wall behind our listening seat, should it be totally absorbent instead of
the normally suggested which calls for diffusion. Would appreciate your thoughts on this. I have experimented with diffusion but the benefits don't seem to be as great as diffusion on the front wall
Thanks
Member
Joined 2009
Paid Member
How did you know my main speaker is a mono open back box 
It’s more a Boffle than a dipole. With single driver and whizzered the treble is fed firing only.
But it’s not simply room size- plenty of people want their speakers near the front wall. Jordan shows a typical(?) HT set-up which I see as attractive. But so far I don’t really see how it works and whether it can compete with other approaches.
My old DIY OB’s were stereo and used in the basement, I never tried them close to the front wall. If I wanted to do so I’d go down the Boffle route.
It’s more a Boffle than a dipole. With single driver and whizzered the treble is fed firing only.
But it’s not simply room size- plenty of people want their speakers near the front wall. Jordan shows a typical(?) HT set-up which I see as attractive. But so far I don’t really see how it works and whether it can compete with other approaches.
My old DIY OB’s were stereo and used in the basement, I never tried them close to the front wall. If I wanted to do so I’d go down the Boffle route.
just an example
in fact any good on-wall (or short up-firing) speakers in Beveridge side-wall positioning which gives best results in any rectangular room
The throat of a horn is the same size as the driver or smaller and not greatly larger as in this case, the throat in a horn cannot include a gap which would relieve the pressure, a horn has a progressively increasing area which requires enclosure on all sides not just 2 sides. The space between the panel and the wall will not act like a horn.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.